When we were working on venn diagrams on Tuesday, we added a third circle to the equation.
The diagram above is a good example of what each section represents. And like last week, we were finding the union, intersection, and compliment of three factors. As a refresher, the union of the equation would be all of the circles. The intersection of A and B is AB, of A and C is AC and of B and C is BC. The intersection of all three factors is the place in the middle, represented by ABC. These types of problems can be tricky, and it is difficult to figure them out without shading. A good website that allows you to do a few given problems, and is also a good reference for practicing shading, is
Thursday's class period was chalked full of properties and important things to remember. I will define these terms and properties below:
Set Problem - A set problem gives distinctly different variables of the problem.
EX: Tyler has 2 small chocolate doughnuts and 3 small powdered doughnuts for breakfast. How
many did Tyler eat altogether?
A problem like this is going to confuse a young student because they will not make the connection that the two different kinds of doughnuts should be added.
Measurement/Number Line Problem - This problem is like the above problem although it does not make the distinction between the two variables being added together.
EX: Tyler has 2 small doughnuts for breakfast. His mom lets him have 3 more small doughnuts.
How many did Tyler eat total?
There are three properties of addition. These properties are very important to know, and is very important for teachers to focus on explaining why things are the way they are instead of simply making students memorize facts.
Commutative Property - a + b = b + a, or, 6 + 4 = 4 + 6
No matter the order, things will add up to have the same answer.
Associative Property - a + (b + c) = (a + b) + c, or, 2 + (8 + 4) = (2 + 8) + 4
This property is grouping together the parts of the problem that will look easier in your head, such as making a 10 with the 8 and 2, instead of a 12 with the 4 and 8. It is OK to move the parentheses.
Identity Property of 0 - a + 0 = a, or, 8 + 0 = 8
Adding zero to a number will not change the number, Therefore, the sum will be the number that is being added to zero.
Teaching these properties as well as relationships of numbers such as knowing which numbers are one of two more or less than any given number, what it takes to reach a 5 or a 10 from a number, or what the double of a number is, is very important for students success.





